Ignition coil



May 19, 1942 H. L. HAR'rzr-:LL Erm. 2,283,733

IGNITION COIL Filed Sept. 28, 1959 dem Patented May 19, 1942 i IGNITION COIL Herman L; Hartzell and Dalphin L. Hittle, Anderson,

Ind., assignors to General'Motors Corporation, Detroit, Mich., a corporation of Delaware Application September 28, 1939, Serial No. 296,906

7 Claims.

This invention relates to ignition coils for automotive use, and is concerned particularly with oil or wax impregnated coils, or those coil bodies that are rigidly secured within a casing that is hermetically sealed to insure against fluid now through any of the junctures of the enclosing casing or through any of the circuit terminal mountings. A form of coil to which the present invention relates is disclosed inthe copending application of Herman yL. Hartzell, Ser. No. 296,904 filed September 28, 1939.

It is an object of the present invention to provide certain improvements in the type of coil disclosed in the Hartzell application referredto, with the aim, to reduce the cost of manufacture of coils having fluid tight enclosures, in which' the coil body can be properly located so that the impregnant can reach all parts of theenclosure and the voids of the assembly. A

A further object of the invention is to improve the means for providing a fluid tight seal between the coil container of'thin sheet metal and the high tension terminal of porcelain.

Further objects and advantages of the present invention will be apparent from the Vfollowing description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a view partly'in elevation and partly in section, illustrating the instant invention substantially as indicated by the line and arrows I-I of Fig. 2.

Fig. 1A is a sectional detail of seam construction.

Fig. 2 is a top pian view' 0f in@ ignition coil i substantially as indicated by the arrow 2 of Fig. 1. y

Fig. 3 is a transverse sectional view substan-` tially as indicated by the line and arrows 3-3 of Fig. 1,`it showing a plan of the core cup.

Fig. 4 is a transverse sectional view substantially as indicated by the line and arrows 4-4 of Fig. 1, and showing the Winding locator in plan. n

Fig. 5 is an enlarged detail view in section showing the construction of one of the primary terminals.

Fig. 6 is a similar type view showing the details of construction of thehigh tension terminal. With specic reference to the drawing, I0 refers to a sheet metal coil case having a longitudinal lock seam I2 (Fig. 4). and being closed at each end by members I4 and I6. Member I4 supports circuit terminals as I8 and 20. End member I6 supports terminal 22. Enclosed withinterlocked with the end of .which is the I6 there is a y.. terminates inside drical portion 52,

in the casing is a coil assembly unit 24, including a bundle of core wires 26 supporting a secondary winding -21 and about which is wound a primary winding 28. A lead from the inside end of the secondary winding 21 is tucked in between the core wires 26 in the usual manner, and the outside secondary winding lead and the inside primary winding lead are twisted together and -fastened by a clip 30, :from which a lead 32 makes connection with the primary terminal I8. The outside end of the primary winding is joined to a lead 34 byl a clip 35, and this lead is secured to the -other primary terminal 2D. The end members I4 and I6 may be secured to the ends of the case member I 0, in any desired manner that will effect a sealed4 juncture, but it is preferred that this be accomplished by a double rolled seam incorporating a gasket 31 (Fig. 1A) of oil and heat resistant material, such as rubber or latex bonded cork. Seam junctures of that type are indicated at 36 and 38, by which the end members I4 and I6 are each secured to one end of the case I0. Contributing to that type of ,seam each of the end members initially has an open rolled edge 40 (Fig. 6), that is finally the case I0.

The speciic construction of the end member I6 is illustratedin Fig. 6, where it will be seen that vthe member has a raised rim 42 bounding open kroll 40. Centrally of member depressed portion 44 that is apertured at 46 for reception of a high tension terminal insulator 48 having a flange 50. The insulator 48 is of porcelain or like material and of the member I6 with a cylinthere being a longitudinal bore or passage 54 therethrough, which is reduced at 56, the outside end. A compressible gasket-58 of oil and heat resisting characteristics is disthe insulator which it closely fits and is pressed against the .inside surface or the bottom wall of the depression 44. The outside diameter of the part 52 is of a dimension to closely t the apertures of the member I6, the gasket 58 and the ring 6I).V

These parts I 6, 48 and 68 are held in iluid tight relation by means of a terminal assembly consisting of a tubular member 62 in the outside end of which is vsecured a hollow terminal tip l1:54, which may be accomplished by hydrogenend of the tube 62 and against the flange 68,"

Where it seats in an end depression 12 in the end of the insulator 48. tube 62 there is disposed a rigid/insulating washer 'I4 that rests against thefendofvthe cylindrical portion 52 and engages at its periphery the inside wall 16 of the insulator ring 60.. The

insulator 14 is of such rigidity as to hold the'end of the tube 62 centrally of the ring 60 and there-V by equalize the tension of the final assembly. To secure these parts resiliently in the assembled relation, one ormore spring steel dished washers 18 are placed over the end of the tube'62 and pressed forceably against the end of the ring 60 where theyA are held until the end of the tube 62 isspun over-as at 80 or otherwise expanded in a riveting relation to'engage and compress'the spring washers 18. That procedure somewhat attens' out the dished washersv 18 and compresses the gaskets 58 and 10 into iiuidl tight relation between rigid parts of the assembly,rand provides a tubular terminal member extending fromA end to'end of the insulator 48, while insulatingly supporting the terminal member by the end member I6.

The high Vtension terminal member 22 being secured in this fashion, the end member I6 is placed over vthe end of `the case I where the open -roll 40 of the end member and the end of the case are secured together as indicated at 3B in Figs. 1 and 1A. The partly closed casing is now ready for reception of the coil parts completingthe assembly. The tubular case I0 has an inwardly extending annular rib 82 A(Fig. 1) that forms a seat for the end of an outside iron assembly 84, that closely engages the inside of the case I0 and surrounds the coil assembly unit 24.

Withjthe'coil casing, I0 lheldin position with the high tension terminal down as shown in Fig. l, and withone end of the outside iron 84` resting against the rib 82a tubular spacer 86 is passed overthe outside of the porcelainwasher 60 and ispressed against Vthe end member I6. Then a winding locator 88 isA passedover the end `of the core wires .26.,remote from the leads 32 and 34 and is moved up against ,the end 'of the secondary winding 2l. The locator 88 is illustrated in detail in Fig. 4, 4and is composed of some molded insulating material, fashioned in general triangular form to provide the flat sides 90,-con-v nected by rounded corners 92 having the same radius of curvature as the inside surface of the outside'iron assembly 84'. Atthe centerof the locator 88 there is an aperture 94 that closely fits aboutthe rbundle of inside ,core wires 26. The surface of the locator ,88 that is disposed away from the winding 21 has arclikedepressions 96 and 98 arrangedin pairs and connected by radially extending grooves |00 (Fig. 4). That formation provides arclike `ribs |02 extending between'each lpair of depressions 96 and 98 which form seats adapted to engage onerend of the spacen'tube 86 Aas* shown in Fig. l.v

The'winding assembly 24 assembled Vwiththev winding locator 88u on the end of the core wires 26 over the inside end of thev is now passed within the casing assembly so that the rounded corners 82 engage within and slide along the inside of the outside iron assembly 84, and until the ends of the core wires 26 engage the end of the tubular member at 80, and until the winding locator 88 engages the tubular spacer 86 which presses the spacer 86 against the end member I6. An outside insulator tube |04 is next passed over the winding assembly 24 and pushed down inside of the coil of outside iron 84, -so that the end of the tube |04 rests against the smooth side of the rounded corners 92 of the winding locator 88. The tube |04 is a little larger in inside diameter than the outside diameter of thewinding assembly so as to provide an annular space |08 between them when they are assembled.

An insulating washer |I0 is then passed over the end l.of the core wires 26 and pushed down against the end of the secondary winding 2l which-is followedby a tubular spacer I|2 o1" insulation that engages the washer |I0 and surrounds the ends of the core wires' 25; Then, there follows a combined core cup and winding locator I I4 -that engages the end of the core wires 26, tubular spacerV I I2, outside'insulator |04, and outside iron assembly 84.

The locatingmember ||4 (Figs. 1 and 3) is made of molded vhard insulating material and comprises a plate portion bounded by arcuate ribs ||6 and I|8 circumferentially spaced and joined by the fiat sides I20.` The arcuate side I I6 has a notch' |22 for receiving the longitudinal seam I2 of the' case I0, which prevents relative rotation of the locator'andf the case.A One face of the member I I4 is fashioned to include a skirt |23 providing a socket |24 for receiving the core wiresV 26. The skirt |23 closely surrounds the tubular spacer I I2. For strengthening the member I I4, struts or radially extending ribs |26 join the outside of the skirt |23 to the plate portion and the ribs at theperirneter of the same.

When assembling the core-cup and winding locator II4 upon the winding assembly, the lead 34' from the winding assembly is passed through an aperature I 28 in the member II4, while the lead 32 is adjusted to lie against one of the ilats |20,A after which the member ||4 is placed over the end of the core wires 26 and is pressed down Within the casing I0 until the ribs IIB and II8 engage the ends of the outside iron 84 and the tubular insulator |04. Continued pressure oi this member forces the entire winding assembly and tubular spacers against the high tension terminal end member I6, where the parts are held in firm and centralized relation by a plurality orstakings or inward dents in the casing I0, as at |30.

The coil assembly is now ready for the top end member I4 supplying the primary terminals I8 and 20. Inasmuch as both of the terminals I8 and 20 are substantially the same, and are similarly supported and insulated, a detailed description of one of them is suiiicient. In Fig. 5, there is shown in detail the construction of the terminal I8.v The-end member I4 supporting the terminals has a pair Aof apertures I3?l and |34 for passing of the terminals I8 and 28 respectively, substantially as shown in Fig. 1. Around the aperture |32, (Figs. 1, 2 and 5) the end member I4 is provided with a ridge |36 concentric with the aperture. Around the aperture |34 (Fig. l) a lockplate |38 is concentrically arranged. Both the rib. |36 and the. lock-plate |38 are incorporated on the outside surface of the end member I4. Centrally disposed on the inside surface of member I4, there is a terminal plate |40 having square apertures |42 and |44 coincident with the apertures |32 and |34 in the end member I4. The terminal plate |40 has a peripheral ilange I 46 normal to the body thereof and that extends away from the end member I4, and which is designed to closely fit within the end of the case I and to assist in the formation of the seam 36. Before any of theterminals are assembled with the end member I4, the lock plate |38, the terminal plate |40 and end mem,- ber I4 are secured together in any preferred man ner as by spot welding. l

The structure of either of the terminals |8 or 28 comprises a tubular member |48 (Fig. 5) having a bore I 50 extending therethrough for reception and securing of the leads 32 or 341 as the case may be. there is a flange I 52 having a peripheral rib |54 for surrounding and retaining a gasket |56 of oil and heat resisting material that closely surrounds the mounting portion |58 of the member |48. an insulating washer |60 that is followed by another compressible gasket |62 of oil and heat resistant material. The mounting portion |58 of the terminal is somewhat smaller in diameter than the diameter of the aperture |32, so that when the gasket |62 is centered within the rib |36 and compressed against the end member |4, part of the gasket will be forced into the aperture |32 to insure insulation between the parts. The terminal I8 with this assembly of parts is afiixed to the end member I4 by passing the portion |58 through the aperture |32 whereupon a square insulating washer |64 is forced over a knurled part |66. Since the washer is square and ts within the square apertures of the Yterminal plate |40, the terminal I8 or is prevented from turning relative to its support. The terminal I8 or 20 is secured in place by means of spinning or otherwise turning over the end of the tubular member |48 as at |68, to at least partially compress or vflatten out a spring steel dished washer |10 that is disposed against the square insulating Washer |64 around the mounting portion |58 of the terminal. By forcefully pressing the parts together when spinning the end at |68, such compressive force is exerted upon the gaskets |56 and |62 as to effect a sealed connection, proof against fluid ow through the end member |4. I8 and 20 being. thus mounted, the leads 32 and 34 are connected to them by passing bared ends of the leads through the bores |50 where they are soldered as is the usual practice, which also seals the bores |50 of the terminals I8 and 20 against leakage. Then the end member I4 is assembled with the case I0 and the casing members secured in a sealed relation by the rolled joint 36 similar in construction to the rolled joint 38 of Fig. 1A.A The coil is then stacked with others in a kettle where it is evacuated and impregnated with a suitable oil or wax, and under a condition of heating to a temperature above the normal operating temperature of the coil, This is accomplished through the single opening to the interior of the coil construction provided by the tubular member 62 forming the conductive core of the high tension terminal. When the impregnation is completed, and while the coil is still at the high temperature, the case I0 is hermetically sealed Intermediate its length,

There is next placed on the part |58 I minal tip 64 where it is secured in iluid tight Vthe armor |80 is attached. When the extension lock switch coil thus provided is installed upon a vehicle the armor |80 is stretched so taut as to prevent such flexing of the armor as Would permit relative rotation of the coil and cover |18 that might result in separation of the parts and give access to the electrical connection to the terminal 20. Contributing to this end the terminal cover |18 and the lock plate |38 are' joined by a bayonet type of coupling that requires something like 60 relative rotation for coupling and uncoupling. This coupling is described in detail in our copending application Ser. No. 296,905, led September 28, 1939.

When placed in service, the coil is mounted in the position indicated in Fig. 1, or so that the high tension terminal is down. That is accomplished by means of a mounting bracket or band |16 secured to the case I0 and having apertured lugs for the reception of suitable screw devices.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

l. An oil or wax impregnated ignition coil, comprising in combination, a tubular metallic casing, metallic end members secured to the ends of said tubular casing in sealing relation, an outside iron assembly lining the tubular casing, a coil body having windings, means centralizing the windings with respect to the casing and including winding locators, one at each end of the coil body, means including the winding locators and inward extensions of the tubular casing for holding the windings and outside iron assembly against shifting in the casing, there -being circumferential spacing between the coil Both terminals y 'by driving a plug |12 into the end of the ter- 75 body andthe outside iron assembly for the reception of an impregnant.

`2. An oil or wax impregnated ignition coil, comprising in combination, a tubular metallic casing, metallic end members secured to the ends of said tubular casing in sealing relation, an outside iron assembly lining the tubular casing, said casing having an inward extension near one end of the said assembly, a winding assembly within the casing and circumferentially spaced from the iron assembly, winding locators disposed at each end of the winding assembly, and means spacing the winding locators from the end members including inward extensions at the other end of the tubular case.

3. An oil or wax impregnated ignition coil, comprising in combination, a tubular metallic casing, metallic end members secured to the ends of said tubular casing in sealing relation,

casing and circumferentially spaced from the iron assembly, winding locators disposed at each end of the winding assembly, a tubular spacer one of the winding locators','and means forcing the winding assembly Vand the iron assembly against that end member including inward extensions of the case abutting the other winding locator.

4. In an oil or wax impregnated ignition coil, comprising, a'tubular metallic casing, and metallic end members secured to the ends of said tubular casing in sealing relation, with a coil body including windings and a core inclosed within the casing, and wherein said core extends at each end beyond the windings, the combination comprising winding locators spaced from the end members of the casing and disposed about each end of the core and supported by the sidewalls of the casing for equally spacing the coil body with respect to the casing and means disposed between each of the winding locators and the end members for locating the coil body longitudinally of the casing.

disposed between one of the end vmembers and 5. The combination 'set forth in claim 4 in which one of the winding locators comprises a cup engaging one end of the core and is held in place by inward extensions of the tubular case.

6. The combination set forth in claim 4 in which the means engaging the locators includes a tubular spacer centrally disposed with respect to the tubular casing and pressing at one end against one of the end members.

7. The combination set forth in claim 4 in which one of the winding locators has a recessed surface providing arclike ribs concentric to the core, and in which the means spacing the locator -from the end member is a tubular spacer one end of which rests lupon said ribs of the locator, whereby fluid flow is possible from inside to outside of the tubular spacer.

HERMAN L. HARTZELL. DALPHIN L. HITTLE. 

